1. Technology Field
The present invention relates to a data access method, a memory controller and a memory storage system and particularly to a data access method capable of configuring a write-protect area and a writable area in one partition, and a memory controller and a memory storage system using the method.
2. Description of Related Art
Digital cameras, cells phones, and digital music players have undergone rapid growth in recent years, so that consumer demand for storage media has also rapid increased. Rewritable non-volatile memory is one of the most adaptable memories for such battery-powered portable products due to its characteristics such as data non-volatility, low power consumption, small volume, and non-mechanical structure. A memory card is a storage device adopting NAND flash memory as storage medium. A memory card has been broadly used for storing important personal data thanks to its small volume and large capacity.
Because the capacity of flash memory becomes much larger than before, a user usually formats the available storage spaces of a storage device adopting flash memory as storage medium into a plurality of partitions by a file system for using respectively. For example, some important data is stored in one of the formatted partitions and this partition is set as a write-protect area, thereby preventing the important data from being mistakenly deleted. However, according to the standard of a memory card (e.g., a secure digital (SD) memory card and a multi media card (MMC), etc.), the memory card can not support the function for a plurality of partitions. Namely, the storage spaces of the memory card can not be formatted into a plurality of partitions for accessing by a host system. Accordingly, the storage spaces of the memory card only are formatted into one partition and are set as the writable area or the write-protect area in unit of the entire partition.
Therefore, a user often needs to set a memory card, which only stores a little of data, as being at a write-protect mode, and thereby unused storage spaces of the memory card will be wasted. For example, when a manufacturer producing navigation machines applies a memory card having 16 gigabytes (GB) of storage spaces, as storage medium for storing navigation software and map information of 2 GB of data size, the memory card is set as being the write-protect mode with only storing 2 GB of data volume in order to prevent the navigation software and map information from being deleted mistakenly by a user. Accordingly, unused storage spaces of the memory card will not be used any more.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the present invention. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention, or that any reference forms a part of the common general knowledge in the art.